JnPS
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Packet Desicants
Just curious if anyone has ever tried using those silica gel packets as a poor chemist's drying agent for storing solid chemicals.
I recently made a batch of pTSA but the bottle I keep it in is plastic and has a lot of head space. I figured if I had a glass bottle for it I could
flame dry it to keep the crystals dry but since its plastic I thought maybe adding one of those common dehydrating silica gel packets could serve to
keep it dry until I find a suitable glass bottle without contaminating the product.
Has anybody here tried this or have knowledge on whether it could/couldn't work?
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LD5050
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I like to go to harbor freight and get the silica beads they use to dry the compressed air that leads to the guns they use for auto body painting. The
beads are blue when they are dry and when they are saturated with water they turn pink. You can then dry them in the microwave and they turn blue
again. They work great. I use them in my desiccator and they really work awesome. They are cheap too and you can get a bunch.
I suppose you could take some and wrap them in a coffee filter and put them in the head space of the container holding your material you want to dry.
I actually use a metal tea container with a plastic snap on cap.The container has a bunch of tiny holes throughout it. It is used for putting ground
tea leaves in and you drop it in a cup of hot water to make your tea and the tea leaches through the holes. I just fill it with the silica beads and
put it in what ever container of material I want to dry and check it periodically to see if the beads are pink and if they are I dry them and re use
them.
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XeonTheMGPony
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I use the cobalt chloride doped silica gell too, same source but I mix it with the packets I find or get when I buy stuff, more the better, regenerate
at 240c for a couple hours.
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Melgar
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A bit of advice our British members might be especially appreciative of: cutting the top edge off of a teabag, filling it silica gel, then sealing it
with tape or staples or whatever works, is a nice, simple way to make desiccant packs. Also, Hot Hands hand warmers make awesome oxygen scavengers
for any oxygen-sensitive reagents. They're just reduced iron with some catalysts that make them rust faster.
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LD5050
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How do you go about using the hand warmers for keeping oxygen out of oxygen sensitive reagents?
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Cryolite.
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Regardless of the nice idea of using silica to keep reagents dry, I don't think it will work with pTSA: toluenesulfonic acid is nearly as hygroscopic
as sodium hydroxide, and it will actually get wetter if you try to dry it in a dessicator with calcium chloride. The calcium chloride will actually
lose its absorbed water to the chemical you're trying to dry.
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